Due to demonetisation real estate sector is having a hard time but in the days to come it will definitely gain momentum. But even in this time three cities Delhi, Mumbai, Bengaluru are must invest in cities where you don't have to think about before investing. According to the stats these cities are best for the earning returns of the purchase. Once the market gets back to normal, you would be one of the early birds to enjoy the benefits when prices are still low.